First of all, thank you for providing such a versatile tool. The German language Wikipedia community are discussing the provision of a deep link to the Authorship section of the Page History tool right now, to be displayed alongside every article. Should the vote come to pass, I would expect to see an increased load on the Page History tool in a few weeks' time. So I hope that there is some caching mechanism.
I would like to ask for a change in the Authorship section. Right now, the rendering of the pie chart takes only the percentages of the first ten contributors into account. If an article has a long tail distribution of contributors, this gives the wrong impression. The top ten contributors to the article Angela Merkel have contributed less than 40% of the current total to the article. Yet the pie chart makes it look as if the #1 contributor has contribued more than a quarter to the article, not 11.7 %. Could you please change the rendering of the pie chart so that the remaining other contributors (lower ranked than #10) get one collective slice of the pie, being as large as their combined total? This pie section could be gray, as this connotes lack of detail. In the Angela Merkel example, this slice of the pie would be 61.5 %, or about two thirds. The ten named top contributors would get proportionally smaller slices.
Thank you! (PS: I am not sure whether I get a feedback or ping through this site, so if you want to contact me, better try my de:WP talk page.)